The disclosure relates generally to the field of food product processing, and more particularly methods and systems for optimizing laser markings on food products. While reference is made herein to eggs in particular, it should be understood that this disclosure is directed to all food products in which a laser mark may be applied thereon.
In the egg packing industry, eggs typically undergo a great deal of processing before they are ready to be sold to the consuming public. In many circumstances, for example, eggs pass through several processing stations where they are washed, candled, weighed, graded, and packed into packages (e.g., cartons, crates, or other commercially distributed containers). Examples of such processing stations and mechanisms for conveying eggs from station to station are described, for instance, in the following U.S. patents assigned to Diamond Automations, Inc. (U.S. Pat. Nos. 4,189,898; 4,195,736; 4,505,373; 4,519,494; 4,519,505; 4,569,444; 4,750,316; 5,321,491; and 6,056,341) and TEN Media LLC (U.S. Pat. No. 8,455,030), which are incorporated herein by reference in their entirety. As a reference, it is not uncommon for a facility in which these stations operate to output about one million eggs in a single day. Accordingly, to be commercially acceptable, the throughput of the stations needs to be quite high, with some stations typically processing on the order of 20,000 eggs per hour.
The egg packing industry uses devices known as “packers” to pack the eggs into the packages. Typically, a packer includes a conveyor (e.g., a belt conveyor, roller conveyor, chain conveyor, etc.) that moves empty packages through an egg loading section (where the eggs are loaded into the egg loading section from above) and then moves the filled packages to a package closing section that is responsible for closing the lids of the packages. The eggs may be supplied to the egg packer via a grader system.
An egg packing process that uses “packers,” typically uses bulk belts to bring eggs from a bulk supply location. The eggs are cleaned or disinfected, in some instances using UV light while clamped to transport chains, and in some instances through immersion in sanitizing wash water. The eggs are then inspected either electronically or manually, they are weighed to establish size, inspected for cracks using ultrasonic inspection and loaded into a chain driven carriage mechanism (“Transfer Loader”). The egg is then normally transported to one of a plurality of packing machines by the aforementioned carriage mechanism. The particular packing machine to which any individual egg may be transported is determined by a computer. This process or elements thereof up to, but not including the packing machine, constitute grading (“Grading” and the “Grader”). The carriage mechanism typically consists of one or a plurality of chains, running the length of the Grader past all the packing machines in the horizontal plane (“Grader Chains”). The packing machines are usually configured with an egg flow perpendicular to the Grader Chain in the horizontal plane.
The egg industry widely uses Continuous Inkjet Printer technology (“CIJ Printers”) to print Size, Grade and Date information together with other information or images and logos (“Data”) on to the surface of an egg shell of a fresh egg travelling through an egg grading machine. The CIJ Printers are traditionally placed in a location on the production line that is responsible for grading the eggs and the site for such installation is chosen to minimize the number of CIJ Printers required for a given installation. CIJ Printers have typically been installed on the Grader Chains as near to the Transfer Loader as practical, and typically (although not always), prior to all the packing machines to which almost all eggs are later diverted.
As a consequence of the location, the CIJ Printer provides a relatively economic means of applying Data that limits the number of printing heads. Like most processing methods the execution of these installs represents a compromise of many factors, and the method described above has disadvantages which adversely affect the equipment, retailers, and consumers of eggs negatively. The negative elements of the method described above include:
a) The CIJ Printer's print-head is installed inverted below the flow of eggs;
b) Egg debris or broken eggs can fall into the jetting mechanism of the inkjet printer causing downtime and impeding print quality;
c) The flow of ink is upward and therefore stray ink can fall backwards and result in downtime and maintenance issues;
d) The linear speed of the eggs as they pass the print-head is fast and therefore the amount of data is limited;
e) The linear speed of the eggs as they pass the print-head is fast and therefore the print quality achieved is typically poor quality;
f) The eggs usually travel in the Grader Chain clamped long ways and therefore the print applied to the eggshell is on the side of the egg in a print direction equal to the direction of egg travel (along the long axis of the egg) with such print being normally unreadable by a consumer without handling the eggs in the carton;                a. Handling the eggs in a carton can lead to contamination of the egg; and        b. Handling of the egg in the carton can lead to increased levels of breakage by consumers inspecting eggs in the retail store where they are sold;        
g) A reasonable high proportion of eggs will have very poor or unreadable marks due to a combination of these factors; and
h) If the grader has a minor malfunction, an egg can be inadvertently diverted (or fall) from the Grader at an unplanned Packing Machine (i.e. not the one the computer had intended) because the plurality of packing lanes often process multiple brands of eggs concurrently, a badly branded or sized egg appearing in the wrong carton can be a legal and public relations issue and can cause both consumer and retailer dissatisfaction.
As such, there is a need in the art for a system and method to improve the reliability and quality of applying markings to eggs as well as other food products.